Hydroxylapatite

Crystalline Hydroxylapatite is a structurally organised, highly polar material which, in aqueous solution (in buffers) strongly adsorbs macromolecules such as proteins and nucleic acids, permitting their separation by virtue of the interaction with charged phosphate groups and calcium ions, as well by physical adsorption. The 

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Another example of vims clearance is for IgM human antibodies derived from human B lymphocyte cell lines where the steps are precipitation, size exclusion using nucleases, and anion-exchange chromatography (24). A second sequence consists of cation-exchange, hydroxylapatite, and immunoaffinity chromatographies. Each three-step sequence utilizes steps based on different properties. The first sequence employs solubiUty, size, and anion selectivity the second sequence is based on cation selectivity, adsorption, and selective recognition based on an anti-u chain IgG (24). 

Fig. 12. Phase diagram of the CaO—H2O—P20 (calcium orthophosphate) system where the circle represents the variable hydroxylapatite composition and...

Angiotensinogen (from human blood serum) [643I5-I6-8]. Purified by chromatography on Blue Sepharose, Phenyl-Sepharose, hydroxylapatite and immobilised 5-hydroxytryptamine [Campbell et al. Biochem J 243 121 1987]. 

Dibydropteridine reductase (from sbeep liver) [9074-11-7] Mr 52,000 [EC 1.6.99.7]. Purified by fractionation with ammonium sulfate, dialysed versus tris buffer, adsorbed and eluted from hydroxylapatite gel. Then run through a DEAE-cellulose column and also subjected to Sephadex G-lOO filtration. [Craine et al. J Biol Chem 247 6082 1972.]... 

Dipeptidyl aminopeptidase (from rat brain) [9031-94-1] [EC 3.4.11.10]. Purified about 2000-fold by column chromatography on CM-cellulose, hydroxylapatite and Gly-Pro AH-Sepharose. [Imai et al. J Biochem (Tokyo)93 431 1983.]... 

Interleukin (from human source). Purified using lyophilisation and desalting on a Bio-Rad P-6DC desalting gel, then two steps of HPLC, first with hydroxylapatite, followed by a TSK-125 size exclusion column. [Kock and Luger J Chromatogr 296 293 7984 ]... 

Lectins (proteins and/or glycoproteins of non-immune origin that agglutinate cells, from seeds of Robinia pseudoacacia), M 100,000. Purified by pptn with ammonium sulfate and dialysis then chromatographed on DE-52 DEAE-cellulose anion-exchanger, hydroxylapatite and Sephacryl S-200. [Wantyghem et al. Biochem J 237 483 1986.]... 

Pertussis toxin (from Bordetella pertussis) [70323-44-3J Mr 117,000. Purified by stepwise elution from 3 columns comprising Blue Sepharose, Phenyl Sepharose and hydroxylapatite, and SDS-PAGE [Svoboda et al. Anal Biochem 159 402 1986, Biochemistry 21 5516 79[Pg.557]

Alkaline phosphatase from rat osteosarcoma has been purified by acetone pptn, followed by chromatography on DEAE-cellulose, Sephacryl S-200, and hydroxylapatite. [Nair et al. Arch Biochem Biophys 254 18 1987.]... 

Murine macrophage colony-stimulating factor obtained from mouse L cells can be purified more efficiently on a large scale by HPLC in the presence of sodium dodecyl sulfate. The adsorption on hydroxylapatite gel is dependent on the presence of sodium dodecyl sulfate [197]. 

Biomedical materials include ceramics such as the biologically active hydroxylapatite and tricalcium phosphate, and high-strength metals such as titanium alloys.These materials are not produced by CVD as this time, except on an experimental basis. CVD, however, is the major process used in the production of another very important biomedical material, i.e., isotropic... 

C values of carbonate hydroxylapatite range from -148 to -10.3%o in herbivores. They range from -17.4 to -15.4%o in bears, and from -16.1%o to -14.5 in carnivores (Table 4.1). The average values clearly differ between herbivores (-12.7 1.4%o), bears (-16.2 0.6%o) and carnivores (-15.5 0,6%o). The 5 C values of carbonate hydroxy lapatite of bears are slightly more negative than those of other carnivores. 

The difference between the 5 C values of carbonate hydroxylapatite and collagen (A C) of the same individual, range from 5.8 to 9.2 in herbivores, from 2.7 to 5.7 in bears, and from 4.3 to 5.5%o in carnivores (Table 4.1). There is no overlap of A C values between herbivores on one hand, and bears and carnivores on the other. The average A C value is slightly larger in carnivores than in bears, but with a large overlap. 

The 6 C values of carbonate hydroxylapatite of the herbivores are less negative than those of carnivores and bears, with almost no overlap. The 6 C values of carbonate hydroxylapatite of the bears are slightly more negative than those of the other carnivores. As a result, difference between 5 C values of carbonate hydroxylapatite (A C) and those of collagen is larger in herbivores (7.9 1. l%o) than in carnivores (4.7 0.4%o) and in bears (4.0 0.9%o). The... 

Similar 5 C values are measured in carbonate hydroxylapatite for herbivores, carnivores and bears, respectively, in localities from 40,000 to 600,000 years old (Fig. 4.11). The spacing value between collagen and carbonate hydroxylapatite (A C) is larger in Kent s Cavern heibivores and carnivores... 

The following differences have been observed in modern mammals from cold and temperate areas with no C4 plants a slight enrichment in C in collagen between herbivores and carnivores a clear difference in carbonate hydroxylapatite 8 C values between herbivores and carnivores (including bears), and thus a difference between A Cvalues of herbivores and carnivores a clear enrichment in N between herbivore and carnivore bone collagen. 

Figure 4.11. Average collagen ( c ) and carbonate hydroxylapatite ( a ) 8 C values in modem and Pleistocene herbivores, carnivores and bears. Isotopic abundances for modem samples are from this paper, those for Kent s Cavern samples are from Bocherens et al. (1995b) and those for other Pleistocene localities are from Bocherens et al. (1994).

Koch, P.L., Tuioss, N. and Fogel, M.L. 1997 The effects of sample treatment and diagenesis on the isotopic integrity of carbonate in hiogenic hydroxylapatite. Journal of Archaeological Science 24 417--t29. 

Grote JJ. Reconstruction of the middle ear with hydroxylapatite implants Long-term results. Ann Otol Rhinol Laryngol, 1990, 99(144), 12-16. 

The only element that was discovered in body fluids (urine). This is plausible, as P plays a main role in all life processes. It is one of the five elements that make up DNA (besides C, H, N, and 0 evolution did not require anything else to code all life). The P-O-P bond, phosphoric acid anhydride, is the universal energy currency in cells. The skeletons of mammals consists of Ca phosphate (hydroxylapatite). The element is encountered in several allotropic modifications white phosphorus (soft, pyrophoric P4, very toxic), red phosphorus (nontoxic, used to make the striking surface of matchboxes), black phosphorus (formed under high pressures). Phosphates are indispensable as fertilizer, but less desirable in washing agents as the waste water is too concentrated with this substance (eutrophication). It has a rich chemistry, is the basis for powerful insecticides, but also for warfare agents. A versatile element. 

Silver white, relatively soft metal that is only applied in alloys. Oxygen and water attack pure Ca. The most prominent compound is the oxide (CaO) = burnt calcium, which hardens to calcium carbonate in mortar. Annual production of about 120 million tons. Burnt gypsum (CaS04 0.5 H20) hardens with water. A great step in evolution was the replacement of hard shells of brittle calcium carbonate by an internal skeleton of tough calcium phosphate (hydroxylapatite)-protein composite. Calcium is essential for all life forms. The daily requirement is 0.7-1.0 g. Humans (70 kg) contain 1 kg of calcium. Calcium silicate is the main component of cement. Marble is calcium carbonate in polycrystalline form and the favorite material of sculptors. 

Dobolyi and Bidlo [76] determined the phosphorus-containing minerals in Balatien lake sediment, and thus the forms in which the phosphorus responsible for the accelerating eutrophication of the lake are present. Samples were subjected to chemical, electron microscope and X-ray analysis. Hydroxylapatite was identified, but no proof of the presence of other phosphorus minerals was obtained. 

Simon RH, Eelsenfeld G (1979) A new procedure for purifying histone pairs H2A + H2B and H3 + H4 from chromatin using hydroxylapatite. Nucleic Acids Res 6 689-696 Simpson RT (1978) Structure of the chromatosome, a chromatin particle containing 160 base pairs of DNA and all the histones. Biochemistry 17 5524-5531 Simpson RT, Stafford DW (1983) Structural features of a phased nucleosome core particle. Proc Natl Acad Sci U S A 80 51-55... 

Hydroxylapatite column chromatography relies on the selective adsorption of the protein onto the surface of calcium phosphate. The final stage of purification, on a high-performance DEAE column, is carried out just prior to crystallization of the protein. 

Sulfation has also been documented in salivary proteins, specifically statherin. The enzymes in saliva are the first wave of the human digestion process and statherin prevents the precipitation of calcium phosphate in the salivary gland and saliva. Since TPST is secreted along with statherin, sulfation plays a role in digestion by binding hydroxylapatite and preventing its precipitation. 

McCann HG and Path EH (1958) Phosphate exchange in hydroxylapatite, enamel, dentin, and bone. J Biol Chem 231, 863-868. 

Three extracellular P-mannanases (M-1, M-II and M-III) were purifled by anunonium sulfate precipitation (80% saturation) followed by chromatography on a DEAE-Toyopearl 650 M column (4.6 x 35 cm) equilibrated and eluted with 0.01 M phosphate buffer (pH 7.0 ) and by a hydroxylapatite column (1.6 x 25 cm). As shown in Fig. 1, two active fractions (Fraction 1 and 2) were detected after hydroxylapatite chromatography. Each fraction 1 and 2 was applied onto a Sephacryl S-200 column (2.6 x 90 cm) equilibrated with 0.01 M phosphate buffer (pH 7.0) containing 0.1 M NaCl and eluted with the same buffer. Mannanase-I and -II were isolated from fraction 1 and mannanase-III was from fraction 2. 

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